Serial number

US patent specifications display serial numbers, apparently assigned by the USPO around the time of filing. We have not seen documentation about these, and we do not see their full meaning or the range of values. It appears that serial numbers cycle and are reused on later patent applications.

We see illustrative uses. Patent US-1903-745953 refers to earlier US patents by serial number, which may be a US-specific technique to refer to patent applications and perhaps even those which have been granted and have a public final number. Let's see if that's common. Patent US-1912-1081792 refers to Patent US-1912-1081794, strictly by way of serial number and filing date. This process may not seem super-common, in comparison to the addition processes employed within other national systems, but it may be the dominant, possibly the exclusive, American method of addition or reference between patents, when the patents involved are all American.

Patent US-1915-1394816 is an example of a patent using one serial number in association with the patent's application date, and another in association with its date of renewal.

In Sweden, patent filings were recorded on numbered lines in handwritten registers and therefore there was an automatic number associated with each filing, and this might be tracked later. The later patent number would be consecutive with other patents granted at that time.

This may also be the meaning of the Italian register numbers: Registro attestati